title: Complete genome sequence and comparative analysis of the wild-type commensal Escherichia coli strain SE11 isolated from a healthy adult.
abstract: We sequenced and analyzed the genome of a commensal Escherichia coli (E. coli) strain SE11 (O152:H28) recently isolated from feces of a healthy adult and classified into E. coli phylogenetic group B1. SE11 harbored a 4.8 Mb chromosome encoding 4679 protein-coding genes and six plasmids encoding 323 protein-coding genes. None of the SE11 genes had sequence similarity to known genes encoding phage- and plasmid-borne virulence factors found in pathogenic E. coli strains. The comparative genome analysis with the laboratory strain K-12 MG1655 identified 62 poorly conserved genes between these two non-pathogenic strains and 1186 genes absent in MG1655. These genes in SE11 were mostly encoded in large insertion regions on the chromosome or in the plasmids, and were notably abundant in genes of fimbriae and autotransporters, which are cell surface appendages that largely contribute to the adherence ability of bacteria to host cells and bacterial conjugation. These data suggest that SE11 may have evolved to acquire and accumulate the functions advantageous for stable colonization of intestinal cells, and that the adhesion-associated functions are important for the commensality of E. coli in human gut habitat.
authors.affiliation: Kitasato Institute for Life Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
authors.forename: Kenshiro
authors.initials: K
authors.lastname: Oshima
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Toh
authors.forename: Yoshitoshi
authors.initials: Y
authors.lastname: Ogura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sasamoto
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Morita
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Tadasuke
authors.initials: T
authors.lastname: Ooka
authors.forename: Sunao
authors.initials: S
authors.lastname: Iyoda
authors.forename: Todd D
authors.initials: TD
authors.lastname: Taylor
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hayashi
authors.forename: Kikuji
authors.initials: K
authors.lastname: Itoh
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
mesh_terms: D000328:Adult; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000821:virology; D048168:Escherichia coli K12 / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D016680:Genome, Bacterial; D023281:Genomics; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins